Electrical measuring instrument.



Patented lan. 30, |900.

' F. M. BENNETT.

ELECTRICAL MEASURING INSTRUMENT.

(Application led Apr. 29, 1898. Renewed July 3, 1899.)

(No Model.)

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FREDERICK M. BENNETT, OF NEW YORK, N. Y.

ELECTRICAL MEASURING INSTRUMENT;

SPECIFICATION arming peet of Lettere Patent No. 642,563, dated January so, 1900'. Application iiled 29,1898. Renewed July 3, 1899. Serial No. 722,695. (No model.)

T0 ii/ZZ whom t may concern:

Be it known that I, FREDERICK M. BEN- NETT, a citizen of the United States, and a resident of New York, in the county and State of New York, have invented a certain new and useful Electrical Measuringlnstrnment, of .which the following is a specification.

My invention relates to indicators or ourrent-measuring devices for electrical instruments; and it has for its object the provision of an organization of the class described simple in construction, inexpensive to man ufacture, and eflicient in practical'use.

To attain the desired end, this my invention consists in the construction, arrangement, and operation of parts herein set forth.

In the drawings which accompany and form a part of this specification, Figure 1 represents a front elevation of my meter; Fig. 2, a top or plan view with the cover removed; and Figs. 3, 4., 5, 6, and 7 are views in detail of my indication-needle and support therefor.

Like letters of reference indicate like parts in all the views.

I have found it desirable to make a portable electrical instrument of simple construction and which may be either utilized primarily as an ammeter or a voltmeter and also for other purposes as a galvanometergand I have therefore constructed according to my invention an organization of the class described embodying the preferred construction of parts and their mutual relationship, combination, arrangement, and organization in a composite body or structure, as hereinafter described.

Referring particularly to the drawings, A denotes my armature, consisting of an excitable metallic material, preferably a pivoted metallic bar, as a plate of soft iron or a permanent bar-magnet, and either solid or laminated, or consisting of a mass or coil of wire, and constructed and arranged to be deflected by the passage of an electric current through a coil located adjacent to the same and provided with preferably vertical needle points or pivots A2, preferably connected by a bridge A'. My armature A is also provided with a relatively obliquely inclined index-finger A3, terminating in an indicating-point A4. The needle-points A2 ordinarily rest or are loosely set in suitable centers d3, formed in pieces of plumbago, or in jewels D2, placed in the frame or bobbin D, containing means for setting up a magnetic field, as a hollow coil O. The top of my preferably horizontal frame D is ordinarily slotted, as at D', for the insertion therein of the armature, and it also usually supports a guard B to prevent the displacement of said armature when the instrument is inverted. The coil C is provided with terminal binding-posts of ordinary construction, and my instrument also has a scale of practically the same design as those heretofore used, which scale is curved in order to register with the path of movementV of the index-point A4.

Itis manifest that various omissions of some particulars could be made without materially affecting the essential features of my invention or the operation of the remaining parts, and I do not therefore wish to be limited to the specific structural details of the organization herein set forth. Obviously the elements of the structure described may be located at an angle to the plane in which they are shown. I accordingly .use the words horizontal, vertical, and the like in a relative sense.

In practical use the top cover is removed and the armature-pivots are set in plumbago or other centers, whereupon the index will point to zero.

By lengthening the ends or needle pivotpoints the instrument becomes more sensitive, the said points being below the center of gravity, and the obliquely-disposed finger (which may be adjusted by bending the same more or less to one side) acts as a balance for v the excitable metal material, as the plate or armature, and my instrument is rendered more sensitive by reason of the fact that the needle-points and index-finger are obliquely inclined preferably at practically the same angle. It will be observed that the mass of metallic material is set above the coil and is provided with bearing-pivots projecting downward and having eccentrically-located pivots, so that the points of the excitable material will work respectively in and out of said coil, whereby a rocking and eccentric motion of the excitable material is produced.

In Figs. 6 and 7 my excitable material consists of a disk and has a rolling motion down into the coil, the spindle of my needle-points being placed a little ont of the center of theplate in order that the longer end of the same may tend to balance the said index-finger.

I prefer to make my bobbin D of material IOO having a vitreous surface, as glazed porcelain, in which case the centers D3 will be formed in the said bobbin by glazed recesses, the vitreous faces of which thus obviate 'the necessity of using the jewels D2.

As it is evident that many changes in the construction and relative arrangement of parts might be resorted to without departing from the spirit and scope of my invention, I would have it understood that I do not restrict myself to the particular construction and arrangement of parts shown and described, but that such changes and equivalents may be substituted therefor, and that I'Vhat I claim as my invention isl, In combination, a coil, an excitable metallic material set above the coil, and provided with bearings projecting downward and having eccentrically-located pivots so that the outer portions of the excitable material will work respectively in and out of said coil, the said excitable material being provided with an index-finger, whereby a rocking and eccentric motion of the excitable material is produced.

2. In combination, a coil, an excitable metallic material set above the coil, and provided with bearings projecting downward and having eccentrically-located pivots so that the outer portions of the excitable material will work respectively in and out of said coil, the said excitable material being provided with an obliquelyinclined index finger, whereby a rocking and eccentric motion ot' the excitable material is produced.

3. In combination, a coil, an excitable metallic material set above the coil, and provided with bearings projecting downward and having eccentrically-located pivots so that the outer portions of the excitable material will work respectively in and out oi' said coil, the said excitable material being provided with an index-finger, whereby a rocking and eccentric motion of the excitable material is produced, and a guard to prevent the said excitable material from being removed from the coil.

4. In combination, a coil, an excitable metallic material provided with inclined needle points or pivots, so that the outer portions of the excitable material will work respectively in and out of said coil, the said excitable material being provided with an index-finger.

5. In combination, a coil, an excitable metallic material provided with inclined needle points or pivots, so that the outer portions of the metallic material will work respectively in and out of said coil the said metallic material being provided with an obliquely-inclined index-iinger.

6. In combination, a coil, an excitable metallic material provided with inclined needle points or pivots, so that the outer portions of the metallic material will work respectively in and out of said coil the said metallic material being provided with an inclined indexfinger, the incline of the needle-points and index-finger being at practically the same angle.

7. A bobbin havinga vitreous surface and provided with recesses also having vitreous faces, in combination with a pivoted metallic material provided with bearing-points to engage the said recesses.

8. A bobbin having a vitreous surface and provided with recesses also having vitreous faces.

9. In combination, means for setting up a magnetic field, an excitable metallic material provided with bearings projecting downward and having eccentrically-located pivots, supports for the same, the whole so constructed and arranged that the outer portions of the excitable material will work in and out of said magnetic field, whereby a rocking and eccentric motion of the excitable material is produced.

10. In combination, means for setting up a magnetic field, an excitable metallic material provided with bearings projecting downward and having eccentrically-located pivots, supports for the same, the said excitable material being provided with an indexfinger, the whole so constructed and arranged that the outer portions ot' the excitable material will work in and out of said magnetic lield,wherc by a rocking and eccentric motion of the excitable material is produced.

ll. In-combination, means for setting up a magnetic field, au excitable metallic material provided with bearings projecting downward and having eccentrically-located pivots, supports for the same, the said excitable material being provided with an obliquely-inclined index-finger, the whole so constructed and arranged that the outer portions of the excitable material will work in and out of said magnetic field, whereby a rocking and eccentric motion of the excitable material is produced.

l2. In combination, means for setting up a magnetic field, an excitable metallic material provided with bearings projecting down ward: and having eccentrically-locatcd pivots, supports for the same, the said excitable material being provided with an index-finger, the whole so constructed and arranged that the outer portions of the excitable material will work in and out of said magnetic eld,where by a rocking and eccentric motion of the excitable material is produced, and a guard to prevent the said excitable material from being removed.

In testimony of the foregoing speciication I do hereby sign the same in the city of New York, county and State of New York, this 3d day of December, A. D. 1897.

FREDERICK M. BENNETT.

Witnesses J. ODELL FowLEa, J r., M. MCFARLANE.

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